Atrial fibrillation (AF) is the most common cardiac arrhythmia, and is associated with substantial risk of morbidity and mortality. AF currently affects more than 2.5 million Americans and the affected population is steadily growing with our aging society. AF independently increases the risk of stroke by 4- to 5-fold, is an independent risk factor for stroke recurrence, and is responsible for at least 15-20% of all ischemic strokes. In addition to its associated health risks and diminished quality of life, AF is a financial burden on the US Healthcare system, with annual Medicare costs currently estimated at $16 billion. Over the past decade, neuromodulator emerged as an alternative to antiarrhythmic medications and ablative procedures for the treatment of some forms of AF. Applying low levels of electrical stimulation to the vagus nerves inhibits AF inducibility. This innovative form of neural cardiac control is a non-pharmacological, non- ablative modality for the treatment of AF that maintains healthy myocardium. The ultimate goal of this project is to enhance the quality of life for individuals with AF by translating this recent cutting edge research into a clinically viable technology. To date the majority of studies investigating neuromodulation as a treatment for AF were acute procedures. To progress this approach towards clinical application will require the development of suitable devices capable of chronic stimulation. Rosellini Scientific has partnered with Stimwave Technologies Inc. to apply their wireless spinal cord stimulation technology to a form factor and therapeutic treatment protocol suitable for low-level vagus nerve stimulation (LL-VNS) to treat AF. The goal of the proposed study is to evaluate the therapeutic value of LL- VNS for treating AF in a long-term study. To accomplish this goal, we will implant our system in a high-yield canine model of AF and evaluate changes in AF frequency as a result of LL-VNS for a period of 4 weeks. During the experimental period, an implantable pulse generator (IPG) will deliver rapid atrial pacing (RAP) to the left atrial appendage for 6 hours/day to induce AF. Concurrent with RAP, the experimental group will receive LL-VNS from the Rosellini Scientific VNS system, while the control group will receive sham stimulation. The weekly AF burden, defined as the sum of the duration of all spontaneous AF episodes during the period without RAP, will be calculated and compared between groups. For our treatment to be indicated as feasible, we must see e 50% reduction in AF burden for the treatment group versus control. If feasibility is achieved, we will apply to the NIH for Phase 2 funding to determine the appropriate treatment protocol in a chronic study and will submit a U44 to further develop the device.